People with autism are twice as likely to get Parkinson’s disease, experts warn – as both conditions see huge rise
Midlife and older adults with autism are around twice as likely to develop symptoms linked to Parkinson’s disease, a study has suggested.
Autism diagnoses have soared by up to 40-fold in recent years, driven by an increase in the disorder among teenagers.
However, according to the Government’s most recent review there is no evidence that the number of autistic children has actually increased, rather awareness has improved, making people more likely to seek medical help.
Parkinson’s is also on the rise, with 166,000 people in the UK now diagnosed and cases expected to rise significantly as populations age.
Although autism is typically diagnosed early in life – while Parkinson’s tends to develop later – experts now think the two conditions may be linked.
US researchers analysed the health records of 57 million people aged 45 and over and found that autistic adults developed Parkinson’s symptoms at roughly four times the rate of those without the neurodevelopmental disorder.
Around 4 per cent of people with autism diagnoses developed the telltale tremors, muscle stiffness and problems with memory and thinking, compared to just 1.6 per cent of controls.
Parkinson’s is the fastest growing neurological condition in the world. It worsens over time and affects the brain, nervous system and muscle control
Those with intellectual disabilities – such as Down’s syndrome or fetal alcohol spectrum disorder – were also more likely to develop the movement problems (4.3 per cent).
Rates were highest among those with both autism and an intellectual disability, at almost 5 per cent.
The team at The George Washington University concluded this suggested that the cases were not simply due to the co-ordination difficulties associated with autism.
Previous studies have suggested that certain drugs commonly taken by autistic people, such as antipsychotics, can cause Parkinson’s-like side effects.
But researchers said that even after accounting for medication taken by those with autism, the risk remained markedly high.
The study analysed diagnoses of parkinsonism – the group of signs and symptoms characteristic of the disease, which usually result in a diagnosis of the Parkinson’s disease.
Previous research has suggested that dopamine – a chemical that plays an essential role in regulating movement, motivation, learning, and behaviour – could be the hidden link.
Parkinson’s is caused by a decline in dopamine-producing cells in the brain, which results in tremors, rigid, slow movement and problems with balance.
People with autism, meanwhile, appear to process dopamine differently, and this could contribute to behaviours such as repeating actions or routines and finding social interactions more challenging.
While this does not mean autism causes Parkinson’s, scientists are increasingly investigating whether abnormalities in dopamine pathways could help explain the overlap and point to new treatments.
The researchers cautioned that many autistic people experience motor difficulties from an early age, which can resemble Parkinson-like symptoms and make diagnosis challenging – highlighting the need for greater awareness and more routine assessment of these symptoms.
Actor Michael J. Fox, who suffers from the condition, at a Parkinson’s fundraiser… the disease can often leave people needing a wheelchair and relying on physiotherapy to ease symptoms
But further research is needed to determine whether autism itself increases the risk of Parkinson’s or whether the link could be explained by shared biological or environmental factors.
Autism is a lifelong developmental disability which affects how people communicate and interact. There are an estimated 1.2 million people living with the condition in the UK.
But a major review has warned that Britain may be over-diagnosing the condition – because parents have been incentivised to seek a diagnosis for their children by misguided welfare systems that reward such ‘labels’.
Parkinson’s slowly robs sufferers of their ability to live independently. Despite its increasing prevalence, there is still no cure or approved drug capable of slowing its progression.
However, experts believe they are on the cusp of a revolution, with a new generation of treatments designed not simply to manage symptoms but to slow or halt the disease itself.
Some of these drugs could become available within the next three years, while newer medicines that control symptoms more effectively and with fewer side effects could reach the NHS as early as next year.
